Many of Star Trek‘s most well-known aliens look basically human, but sometimes Starfleet encounters truly alien creatures who do not resemble humanity at all. Star Trek: The Next Generation season 6, episode 20, “The Chase” provided an in-universe explanation for why so many Star Trek aliens look like humans with bumpy foreheads. Billions of years ago, a humanoid species now referred to as the Progenitors seeded planets across the galaxy with DNA that would evolve into lifeforms similar to themselves. Star Trek: Discovery season 5 has provided more insight into these mysterious ancient humanoids and their technology.

The practical reason that so many Star Trek aliens are humanoid is, of course, that all actors are human, and, as a television series, there were practical and budgetary limits to how Star Trek could create aliens. More than a few energy-based beings popped up on Star Trek: The Original Series, but they often possessed humanoid hosts or shifted into a human shape so that actors could portray them. Even the Q and the Changelings, who could take nearly any form, take humanoid forms when interacting with humans. In modern Star Trek, humanoid aliens remain the norm, even as make-up and special effects technology has advanced. But it’s always fascinating to see Star Trek aliens who bear little to no resemblance to humanity.

10

The Horta

Star Trek: The Original Series Season 1, Episode 25 – “The Devil in the Dark”

In one of Star Trek: The Original Series’ most iconic episodes, Captain James T. Kirk (William Shatner) and the crew of the USS Enterprise travel to a mining facility to investigate a series of deaths. Once there, they find a strange subterranean creature that is a silicon-based lifeform. When Spock (Leonard Nimoy) mind-melds with it, he discovers that the creature is called the Horta and only killed the miners to protect its eggs.

At the end of Star Trek‘s “The Devil in the Dark,” the miners agree to leave the Horta and its eggs alone, and after the new Horta hatch, they help create tunnels within the mine. While the Horta may look like nothing more than a moving molten rock, it remains one of Star Trek’s most unique aliens. With its classic Star Trek premise, “The Devil in the Dark” remains one of the franchise’s most memorable episodes.

9

The Kerkhovians

Star Trek: Strange New Worlds Season 2, Episode 5 – “Charades”

When Nurse Christine Chapel (Jess Bush) and Lt. Spock (Ethan Peck) do a flyby of the Kerkhovian moon in Star Trek: Strange New Worlds, their shuttlecraft gets pulled into a dangerous vortex. While Chapel is unhurt, Spock has been turned completely human. Captain Christopher Pike (Anson Mount) then contacts the Kerkhovians who “repaired” Spock, but they say that since “remediation” was made, no further contact will be necessary.

The Kerkhovians once built a civilization on the moon of the planet Kerkhov but later moved to interdimensional space. As powerful non-corporeal beings, the Kerkhovians were able to repair the shuttle and heal Spock, but they were confused by Spock’s combination of Vulcan and human DNA. Chapel eventually flew a shuttle into interdimensional space and convinced the Kerkhovians to return Spock to his proper half-Vulcan/half-human state.

8

The Tholians

Star Trek: The Original Series Season 3, Episode 9 – “The Tholian Web” & Star Trek: Enterprise

The Tholians are a crystalline species with a hard outer carapace and six legs who thrive in an extremely hot environment. After Starfleet became aware of the Tholians in 2152, they had several conflicts with one another over the next century. In the Star Trek: The Original Series episode, “The Tholian Web,” Captain Kirk and his crew answer a distress call from the USS Defiant only for the Tholians to show up and order the Enterprise to leave their system.

Governed by the Tholian Assembly, the Tholians are incredibly territorial and are known to kill outsiders for tresspassing in their space. Although small, Tholian vessels can weave an energy web to entrap much larger ships. The Star Trek: Enterprise season 4 two-parter, “In a Mirror, Darkly,” reveals that the Defiant crossed over to the Mirror Universe and was salvaged by the Tholians before being stolen by the Terran Empire.

7

Gomtuu

Star Trek: The Next Generation Season 3, Episode 20 – “Tin Man”

In Star Trek: The Next Generation‘s “Tin Man,” the Betazoid Federation emissary Tam Elbrun (Harry Groener) comes aboard the USS Enterprise-D to initiate First Contact with a sentient spaceship referred to as Tin Man. When Elbrun communicates with Tin Man, he discovers that the creature is called Gomtuu and that it may be the last of its kind. After its crew was killed, Gomtuu wandered the galaxy for millennia before eventually deciding to end its own life.

With a hard and protective outer shell, Gomtuu can grow furniture and equipment inside to support a carbon-based crew. Gomtuu possesses powerful defensive abilities and the ability to transport people even through shields. At the end of TNG’s “Tin Man,” Elbrun decides to join Gomtuu, and the two depart to explore the galaxy. As Elbrun has spent his life feeling overwhelmed by his strong telepathic powers, he finds peace with only Gomtuu as a companion.

6

The Organians

Star Trek: The Original Series Season 1, Episode 26 – “Errand of Mercy” & Star Trek: Enterprise Season 4, Episode 11 – “Observer Effect”

In Star Trek: The Original Series’ “Errand of Mercy,” the USS Enterprise travels to the planet Organia, which lies near the Klingon border. Captain Kirk and Spock head down to the planet to convince the Organians to resist the Klingons, but the Organians refuse any kind of violence. The Organians then reveal themselves to be advanced incorporeal beings capable of incapacitating both the Federation and the Klingon ships.

Although the Organians had once been humanoid, they now existed as pure thought and their actual appearance remains unknown. In Star Trek: Enterprise’s “Observer Effect,” two Organians possess various members of the Enterprise NX-01 crew as they observe humanity to determine whether they are ready for First Contact. Impressed by the crew’s compassion, the Organians heal everyone that was sick and erase all memories of the encounter from the crew’s mind.

5

The Ba’Neth

Star Trek: Voyager Season 6, Episode 6 – “Riddles”

Little is known about the reclusive Delta Quadrant species known as the Ba’Neth, and they were even once regarded as a myth. In 2376, the USS Voyager’s Delta Flyer shuttlecraft encountered a Ba’Neth, which attacked the mind of Lt. Commander Tuvok (Tim Russ). As Voyager’s crew works with a Kesat investigator named Naroq (Mark Moses) to help Tuvok, they learn that the Ba’Neth render themselves invisible using cloaking technology.

Although they typically remained cloaked, the Ba’Neth were known to have tentacles and possessed a large fleet of ships. Tuvok eventually remembers the cloaking frequency used by the Ba’Neth, and Captain Kathryn Janeway (Kate Mulgrew) uses it to find a Ba’Neth space station. After the Ba’Neth admit to attacking ships to assess potential threats, Janeway negotiates with them for information to help Tuvok recover.

4

The Medusans

Star Trek: The Original Series Season 3, Episode 5 – “Is There in Truth No Beauty?” & Star Trek: Prodigy

The Medusans made their first appearance on Star Trek: The Original Series when Ambassador Kollos visited the USS Enterprise with a human engineer, Larry Marvick (David Frankham), and a human telepath, Dr. Miranda Jones (Diana Muldaur). As a non-corporeal Medusan, Kollos had to travel within a special transport chamber, and the appearance of Medusans drove humans and other corporeal beings mad on sight.

Medusans were extremely skilled navigators and possessed telepathic abilities. Zero (Angus Imrie) in Star Trek: Prodigy was a Medusan who escaped from The Diviner (John Noble) and made a makeshift containment suit for themselves. Zero helped fellow prisoner Dal R’El (Brett Gray) steal the USS Protostar and assisted the make-shift crew in their subsequent adventures and attempt to join Starfleet.

3

The Pah-Wraths

Star Trek: Deep Space Nine

As enemies of the Bajoran Prophets, the Pah-wraiths became major players in the final episodes of Star Trek: Deep Space Nine. The Pah-wraiths were incorporeal like the Prophets, but they more regularly possessed people to accomplish their own ends. The Pah-wraiths seemed to feel only negative emotions and those possessed by them often felt lingering rage and hate.

In one of DS9’s most tragic moments, the Cardassian Gul Dukat (Marc Alaimo) released a Pah-wraith, which then possessed him and killed Lt. Jadzia Dax (Terry Farrell). This Pah-wraith attacked the Bajoran wormhole, leading to a war between the Prophets and the Pah-wraiths. Dukat began working with the Pah-wraiths in their plan to destroy the universe, but Captain Benjamin Sisko (Avery Brooks) managed to stop him by sealing the Pah-wraiths within the Fire Caves.

2

The Sheliak

Star Trek: The Next Generation Season 3, Episode 2 – “Ensigns of Command”

In Star Trek: The Next Generation’s “The Ensigns of Command,” the mysterious Sheliak contact the Federation asking them to remove human colonists from one of their planets. Although the Federation has had dealings with the Sheliak in the past, they have struggled to find common ground. Not only are the Sheliak non-humanoid, but their language has proven impossible for Federation scientists to translate.

The Federation eventually established the Treaty of Armens with the Sheliak, a 500,000-word treaty that took 372 Federation legal experts to write. Captain Jean-Luc Picard (Patrick Stewart) finds a loophole within the treaty that gives him the time he needs to evacuate the colonists. The Sheliak have not been referenced on screen since TNG, but they remain a fascinating and complex alien species, despite their belief that humans are lower lifeforms.

1

Species 10-C

Star Trek: Discovery Season 4

As the USS Discovery searches for the cause behind the Dark Matter Anomaly (DMA), they discover the existence of a species located beyond the Galactic Barrier known as Unknown Species 10-C. After their gas giant planet became uninhabitable, Species 10-C created an advanced hyperfield that protected them. They created the DMA to harvest boronite, which they needed to power their hyperfield.

After Discovery crossed the Galactic Barrier, they eventually found a way to communicate with Species 10-C with lights and emotion-conveying hydrocarbons. Once Species 10-C understood that their mining device was destroying sentient beings, they agreed to stop using it. With their atypical way of communicating and their existence as a linked whole, Species 10-C are aliens unlike any other. Hopefully, Star Trek will continue to incorporate unique non-humanoid aliens into its vast universe of species and cultures.

All of the above Star Trek shows except Star Trek: Prodigy are available to stream on Paramount+.

Star Trek: Prodigy is available to stream on Netflix.